In the text it says that you can make a series of Lore vs. Stamina tests while constructing a Contain to generate bonus dice that will eventually add to the Lore vs. Power roll for breaking the Contain. I know what this looks like fictionally to justify the series but I'm curious as to how to perform the series. I see two ways of looking at it:

Each roll is independent and the victories after each roll get set aside and accumulate. So I for roll one I get 1 victory, on roll two and I get 2 victories and on roll three I get 1 victory again so in the end I have 4 dice to add to my Lore when the Contain is challenged.

OR

The roll really is a series in terms of the roll-over mechanic. So on the first roll I score 1 victory so the next roll I roll Lore + 1 vs. Stamina and get two victories and on the third roll I roll Lore +2 vs. Stamina and I only apply the final victories at the end of the chain to the Contain. This adds a great deal more risk to the process.

Given certain (problematic) discussions lately, I'd tentatively say that I was thinking more in terms of the fiction leading. I wanted to provide some iffy-but-possible dice support for someone playing his or her sorcerer being very concerned with getting this Contain just right. As opposed to a dice mechanic that guarantees advantage as long as you put "X" into the fiction.

Also, fiction-first is exactly how this came up last time. The player just started describing all this detail about the contain and my brain said, "Hey, I think there's a mechanic for that! Oh look, there is!"